China got the technology for its first stealth fighter jet from Russia, a senior US lawmaker said Tuesday, one week after the airplane apparently made its maiden flight.

“My understanding is that they built it on information that they received from Russia, from a Russian plane, that they were able to copy,” House Armed Services Committee Chairman Buck McKeon told reporters.

McKeon, a Republican, said he hoped to “hear more” on the issue from Defense Secretary Robert Gates, who was on a visit to Beijing when Chinese state media published photographs of the J-20 fighter in the skies over southwestern China.

According to the reports, which cited witnesses, the next-generation war jet — the existence of which highlights China’s drive to modernize its military — made a 15-minute test flight before landing.